Two Ways to Brew

Cold brew is not iced coffee. Iced coffee is hot-brewed coffee poured over ice — it is bright, slightly bitter, and diluted as the ice melts. Cold brew is ground coffee steeped in cold or room-temperature water for an extended period, then filtered. Because no heat is involved, the extraction process extracts far less of the acidic compounds responsible for sharpness and bitterness. The result is smooth, low-acid, and naturally sweet — a fundamentally different cup.

Choose your mode before you start. Ready-to-drink and concentrate have different ratios and different steep times — mixing them up produces either a very weak or an unreasonably strong result.

Easier · Pour straight over ice

Ready-to-Drink

Ratio 1:10

Example 100g coffee : 1,000g water

Fridge 24 hours (or 10h minimum)

Room temp 10–12 hours

What comes out is ready to drink over ice or with milk. No dilution step. Each cup is poured directly from the batch. Easier to manage and ideal for first-time cold brew brewers.

Efficient · Dilute 1:1 before drinking

Concentrate

Ratio 1:5 to 1:8

Example 100g coffee : 500–800g water

Fridge 24–48 hours

Dilute 1:1 with water, milk, or oat milk

More coffee per litre of finished concentrate. Takes up less fridge space. Dilute to preference when you pour — make it as strong or mild as you like each day.

Always dilute before drinking · Concentrate is not ready-to-drink

The Steep Window

What Happens Over Time

Cold brew is unlike every other brew method — it is measured in hours, not minutes. Temperature controls the speed of extraction; cold slows everything down significantly compared to room temperature. Understanding the extraction window helps you decide when to pull the batch and how to adjust if the cup is too weak or too strong.

Cold Brew Steep Timeline — Refrigerator Method

0–4h

Saturation

Grounds absorb water and begin releasing surface solutes. Very early extraction — mostly acids and lighter aromatics. Not ready. Tastes thin and grassy if tasted now.

4–10h

Early Extraction

Sweetness and fruit notes start to develop. Light-bodied. A 10-hour pull is drinkable as a lighter RTD cold brew — best for a mild, delicate profile.

Min RTD pull

10–20h

Main Extraction

The sweet spot for most cold brews. Chocolate, fruit, and sweetness are fully developed. Body is present but not heavy. This is the 24-hour target window — pull anywhere in here.

Recommended

20–48h

Deep Extraction

Concentrate territory — deep, rich, complex. Used for concentrate ratios (1:5–1:8) where you want maximum intensity before diluting. Body becomes noticeably heavier.

Concentrate range

48h+

Risk Zone

Beyond 48 hours, astringency and bitterness can begin to emerge even with cold extraction. Always pull before 48 hours. Extra coarse grind reduces this risk — finer grinds would over-extract much faster.

Room temperature steeping works faster — typically 10–12 hours for a ready-to-drink result — because molecular activity is higher at warmer temperatures. The trade-off is the cup is slightly less smooth and can carry more acidity than a refrigerator-steeped batch. Refrigerator steeping is more forgiving if you lose track of time, since the cold keeps extraction slow enough that an extra few hours usually does not ruin the batch.

Three Methods

Every Piece of Equipment That Works

Cold brew requires no specialist equipment. The same method works in a mason jar, a French press you already own, or a dedicated cold brew dripper if you want a cleaner setup. All three produce excellent results — the difference is in convenience and filtration.

Mason Jar

Any large jar with a lid + strainer + coffee filter

1 Add extra coarse ground coffee to the jar.

2 Pour cold filtered water over the grounds. Stir to saturate fully.

3 Cover tightly. Refrigerate for 24 hours (or 10h minimum for RTD).

4 Pour through a fine-mesh strainer lined with a paper coffee filter into a second container. Do not press or squeeze the grounds.

5 Seal and refrigerate. Drink within 5–7 days.

Best for

No extra gear Large batches Beginners

French Press

French press you already own — plunger acts as built-in filter

1 Add extra coarse ground coffee to the French press carafe.

2 Pour cold water over the grounds. Stir gently. Place the lid on with the plunger raised fully — do not press.

3 Refrigerate for 24 hours. The French press fits most standard fridge shelves.

4 Press the plunger slowly to the bottom. Pour into a separate container immediately — do not store in the press as grounds continue to extract.

5 For a cleaner result, pour through a coffee filter after plunging.

Best for

Use what you have Easy filtration Convenient

Dedicated Cold Brew Maker

Hario Mizudashi, OXO brewer, or similar

1 Fill the removable filter basket with extra coarse ground coffee.

2 Insert the basket into the carafe. Pour cold water into the carafe until it reaches the fill line.

3 Seal the carafe. Refrigerate for 12–24 hours depending on the brewer size and your desired strength.

4 Remove the filter basket with the spent grounds in one step. No separate straining needed.

5 Pour directly from the carafe. Brew is ready as soon as the basket is removed.

Best for

Cleanest result No straining Repeatable batches

Filtration

Paper vs Mesh — What Your Filter Does to the Cup

Paper Filter

Coffee filter, paper towel, filter paper

Removes virtually all coffee oils and fine particles. The resulting cold brew is clear, clean, and transparent — you can see through it. Flavors are precise and distinct. Acidity reads slightly higher because the oils that would buffer it are absent. Sediment in the cup is negligible.

Cup character

Clean, clear, high flavor clarity. Less body. Closer to a filtered brewed coffee in texture.

Mesh / Cloth Filter

Fine metal mesh, cheesecloth, nut milk bag, French press plunger

Allows coffee oils and some fine particles through into the cup. The result is darker, more opaque, and heavier-bodied. Coffee oils contribute to perceived sweetness and mouthfeel. Some sediment at the bottom of the cup is normal — let it settle before drinking the last third.

Cup character

Rich, full-bodied, slightly oily texture. More weight on the palate. Traditional cold brew character.

Neither is correct. Paper filter produces precision; mesh filter produces richness. The coffees recommended for cold brew — Forest, Eagle, and West — all have enough body and natural sweetness to work well with either. If you are using a French press as your brewer, you are already using a mesh filter. If you want a cleaner result from the French press method, pour through a paper filter after plunging.

Storage

Shelf Life and How to Keep It

Concentrate Shelf Life

Undiluted cold brew concentrate in an airtight container in the refrigerator keeps for up to two weeks. The high coffee concentration acts as a mild preservative. Store in a sealed glass jar — not the brewing vessel.

Ready-to-Drink Shelf Life

Ready-to-drink cold brew at 1:10 ratio keeps for 5–7 days refrigerated. Once diluted — with water, milk, or oat milk — drink within the same day. Diluted cold brew oxidises quickly and loses both flavour and freshness within hours at room temperature.

Signs It Has Gone Off

Stale cold brew develops a flat, cardboard-like taste and a noticeably vinegary or fermented smell. If it smells off, discard it. It will not make you sick — cold brew brewed in a clean container in the fridge does not spoil in a dangerous way — but the cup will taste unpleasant.

Dialling In

When the Batch Is Wrong

Bitter / Harsh / Astringent

Grind too fine, or steep too long

Coarsen the grind — fine particles over-extract rapidly over 24 hours even in cold water. If grind is already extra coarse, reduce steep time by 4–6 hours on the next batch. Also confirm the batch did not exceed 48 hours.

Weak / Thin / Watery

Grind too coarse, ratio too high, or under-steeped

Extend steep time by 6–8 hours and retest before changing the ratio. If still weak after the full 24 hours, grind slightly finer or increase the coffee dose. For concentrate: the ratio may be too close to 1:10 — move toward 1:7 or 1:5.

Muddy / Gritty / Opaque

Grind too fine, or inadequate filtration

Extra coarse grind is essential — fine particles pass through any mesh filter and cannot be removed once in the brew. For the clearest result, strain twice: once through a mesh strainer to remove the bulk of grounds, then again through a coffee filter to remove remaining fines.

Recommended for Cold Brew

Three Simple Coffee Products Built for This Method

Cold brew rewards coffees with naturally bold character and chocolate or fruit depth — the long, cold extraction produces a cup that is inherently smooth and sweet, but it needs a coffee with enough intensity to read through that process at a 1:10 ratio. Lighter, more delicate coffees can get lost.

Recommended

Forest

Single Origin · Nan Province · Natural Process

Med-Dark · 3 dots

Naturally processed Nan Province Arabica. Deep chocolate, lingering sweetness, full body. The natural process character translates beautifully into cold brew — the fruit-driven sweetness survives the long extraction cleanly.

View Forest ↗

Recommended

Eagle

Blend · Northern Thailand · 100% Arabica

Med-Dark · 3 dots

Warm sugary sweetness, easy drinking, full body. Eagle's Sugary and Sweet Continuum position is ideal for cold brew — the double sweetness cluster produces a naturally round, approachable cold brew without requiring any added sugar.

View Eagle ↗

Recommended

West

Blend · Northern Thailand · 100% Arabica

Med-Dark · 3 dots

Warm nutty base with fruity brightness. West's Nut and Fruit combination produces a cold brew with textural warmth and just enough brightness to stay interesting without sharpness. Works especially well as cold brew concentrate diluted with oat milk.

View West ↗

Cold brew is the only brew method where the variables are set before you go to bed and the coffee is ready when you wake up. Get the grind extra coarse, pick your ratio, put it in the fridge, and leave it alone. Time is doing the work.

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French Press Guide Pour Over Guide All Methods Compared